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Do not assume it will. NVIDIA documents ConnectX-7 400G adapters with different port configurations, and its compatibility listings treat QSFP-DD and OSFP cables as separate categories. Check the exact adapter and switch port, then choose a cable with the required connector at each end.
Why “ConnectX-7 400G” is not enough to identify the port
NVIDIA documents a ConnectX-7 version with a 400G RHS OSFP connection and another with a 400G QSFP112/56/28 RHS connection. The model family name alone therefore does not establish which connector is on a particular card. Find the full adapter part number and verify its port configuration in NVIDIA’s ConnectX-7 product-line documentation.
The switch side matters too: identify the switch model, port connector, and whether the link is intended for Ethernet or InfiniBand. ConnectX-7 adapters support both protocols, but that does not make every cable or endpoint combination interchangeable. NVIDIA’s validated cable information and product documentation should be checked against the actual configuration.
What NVIDIA’s cable listings establish
NVIDIA lists 400GbE QSFP-DD DAC products and OSFP passive copper products as distinct cable groups. Its ConnectX-7 cable table shows QSFP-DD-to-QSFP-DD DACs separately from OSFP-to-OSFP passive copper cables; it does not establish a mixed QSFP-DD-to-OSFP DAC as compatible. See the ConnectX-7 validated cable table.
#1 Best Overall
- OSFP TO QSFP-DD CONNECTION – Provides a direct 400Gbps copper connection between one compatible OSFP Flat-Top port and one compatible QSFP-DD port, allowing mixed-form-factor switches, servers and network adapters to communicate within the same rack.
- FLAT-TOP OSFP CONNECTOR – The OSFP end uses the Flat-Top/RHS form factor designed for equipment with a riding heat sink built into the host cage. It is not the Finned-Top OSFP version commonly used in equipment requiring a connector with an integrated external heat sink.
- 4×100G PAM4 SIGNALING – Designed for compatible 400GAUI-4 equipment using four 100G PAM4 electrical lanes. Both connected devices must support the same 4×100G PAM4 host interface; this passive cable cannot convert between 4×100G and 8×50G electrical modes.
- PASSIVE COPPER DESIGN – The 1m/3.3ft twinax construction provides a short-range, low-latency 400G connection without separate optical transceivers or external power, reducing power consumption and deployment cost.
- VERIFY BOTH DEVICES – OSFP and QSFP-DD describe the physical connector types, not guaranteed system interoperability. Confirm the port form factor, 400G Ethernet mode
NVIDIA’s current LinkX compatibility page lists its 400G QSFP-DD category as Ethernet-only, with a maximum DAC reach of 2.5 m, and its 400G OSFP category with a maximum DAC reach of 3 m. These are category specifications, not guarantees for every third-party cable or system. Check the exact part’s current status and system support before ordering.
Choose the cable by both endpoints
- Identify the NIC. Record the complete ConnectX-7 adapter part number and confirm whether its 400G port is OSFP or QSFP112/56/28.
- Identify the switch port. Confirm the switch model, connector, and supported protocol for the intended link.
- Match both cable ends. Select a cable whose connectors match the NIC and switch. NVIDIA’s cited listings distinguish QSFP-DD-to-QSFP-DD from OSFP-to-OSFP rather than validating the mixed pairing.
- Check reach and qualification. Confirm the cable type, length, and current manufacturer qualification for the adapter, switch, and protocol together.
If both ends are OSFP
If the specific ConnectX-7 card is confirmed to have an OSFP port and the switch endpoint is also OSFP, an OSFP-to-OSFP passive DAC is the relevant cable category to investigate. NVIDIA’s ConnectX-7 cable inventory includes OSFP-to-OSFP passive copper models, including 1 m and 2 m entries. Verify the exact part number, lifecycle status, reach, and support for the equipment in use; a listing for that pairing does not validate a different connector combination.
Rank #2
- Fully Compatible with Supermicro CBL-NTWK-0957-QSFPDD-1
- Direct-Attach Cable (DAC), 400Gbps Data Rate
- Twinax Copper, Passive, 30/26AWG, 1 Meter
- QSFP-DD to QSFP-DD Connectors, 40G/100G/200G/400G Applications
- 5 YEAR WARRANTY
If both ends call for QSFP-DD
NVIDIA’s ConnectX-7 cable inventory also lists 400GbE QSFP-DD-to-QSFP-DD copper DAC models from 0.5 m through 3 m. This is relevant only when both endpoints call for that cable category. It is not evidence that one QSFP-DD end can be paired with an OSFP end. For NVIDIA’s listed 400G QSFP-DD category, the compatibility page specifies Ethernet-only and a maximum DAC reach of 2.5 m; check the exact cable listing and system qualification rather than treating the inventory’s range as a universal compatibility guarantee.
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Rank #4
- Fully Compatible with Meraki MA-CBL-40G-3M
- Direct-Attach Stacking Cable (DAC), 40Gbps Data Rate
- 40GBASE-CR4 Twinax, Passive, 3 Meters
- QSFP+ to QSFP+ Connectors
- 5 YEAR WARRANTY
Rank #3
- 200G High-Speed Performance: QSFP56 DAC cable delivers 200GbE bandwidth (450Gbps PAM4 lanes) with ultra-low latency for short-reach data center links
- Wide Compatibility: Hot-pluggable and QSFP56 compliant design ensures seamless operation with data center switches, servers, and network adapters
- Flexible Design: Twinax copper build with 39mm bend radius, ensuring stable routing with low insertion loss and crosstalk in dense rack environments
- Cost-Effective Solution: Direct attach copper cable offers plug-and-play deployment, cutting costs compared to optical modules
- Low Power Consumption: Consumes only 0.03W per end and is RoHS compliant for dense and energy-efficient networks
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